Large kites are used to provide motive force for several sports, most notably kite-boarding and snow-kiting. For example, a rider on a wakeboard-style board, a surfboard, a snowboard, skis or the like can be towed by a kite. Both kite-boarding and snow-kiting involve jumping, where the kite lifts the rider and the board to which the rider usually is coupled, such as by a foot loop, off the surface over which the board had been moving, thereby causing the rider to glide for a distance in a manner similar to a paraglider.
A front control line extending from a leading edge of a kite terminates in what is commonly known as a trim loop or chicken loop. The chicken loop is hooked onto a hook affixed to a spreader bar that is strapped to a harness worn by an operator of a kite, such as the rider of a surfboard being towed by a kite. After the chicken loop is engaged to the hook of the spreader bar, the chicken loop can then be manually locked in place, or shackled.
In addition, rear control lines extending from the trailing edge of the kite are attached to the two ends of a control bar. The operator of the kite uses the control bar to control the kite's flight. For example, when the operator pulls the control bar inwardly toward his body, the length of the rear control lines is effectively reduced, which rotates the kite so that the angle of attack is increased. When tension on the control bar is released, the control bar moves outwardly, away from the operator, effectively lengthening the rear control lines. This lengthening rotates the kite to a position with a lower angle of attack, decreasing the kite's lift. To turn the kite, the operator pulls inwardly only on one end of the control bar, which twists the kite in such a manner that it turns.
Most spreader bars have a simple, U-shaped hook extending therefrom and to which the chicken loop can be attached. In the prior art, the chicken loop is secured to the spreader bar usually by manually inserting a length of plastic tubing, which is attached to one end of the chicken loop, into the space between the two sides of the hook. This securing technique is slow and ungainly both for shackling and unshackling the chicken loop and, therefore, not favored.
In another prior art chicken loop securing technique, a piece of plastic is rotated under a hook extending from the spreader bar. The plastic is snapped into the middle of the hook, locking the chicken loop in place.
Still other spreader bar designs include a manual release utilizing a rotating hook extending from the spreader bar. Such spreader bars include a movable bar, lever or like device positioned in front of the lower part of the hook for preventing rotation of the hook. To release the chicken loop, the bar is moved so that it no longer restrains rotation of the hook. This type of kite release is not a fail safe design, and also has other disadvantages. If the hinge on which the bar rotates fails, the bar can actually be pulled into the middle of the hook as the hook rotates, which effectively locks the chicken loop in place. Similarly, other known chicken loop manual safety releases rely on releasing one side of the chicken loop, thereby allowing the loop to slide through the spreader bar hook. If the release hinge were to fail, the chicken loop would be prevented from sliding through the hook, such that the operator of the kite could not disconnect himself from the kite.
Overall, currently known spreader bar designs rely on an operator removing one hand from the control bar to shackle or unshackle the chicken loop, respectively, to and from the hook and, furthermore, manually activating any available safety release. Recognition of a dangerous situation by a kite operator takes time, and it also takes time for the kite operator to reach for and activate a manual safety release. It has been found that combined human recognition and reaction time is so long that, in many circumstances, the operator cannot act quickly enough to activate a manual safety release before a dangerous situation occurs. Further, in practice, it is difficult for an operator, such as a rider of kite-board, to fly a powerful kite with one hand while manipulating current shackle systems with the other hand to release the kite line.
Also, it is known that most riders, by force of habit, will initially attempt to control a kite when the kite acts unexpectedly, instead of attempting to release the kite. All too often, by the time the rider decides to take steps to release the kite, it is too late to avoid the dangerous situation, which can result in serious injury or death to the rider. For example, an unexpected gust of wind or a kite-control malfunction can cause loftings, which are unintentional flights caused by a kite lifting the rider, and draggings, where a kite drags the rider. Oftentimes, once a rider is being dragged, the rider may not be able to take the necessary physical actions to activate a manual safety release.
Therefore, there is need for an attachment for a tension line, such as a termination of a kite line, which can be releasably engaged to a coupling element of the line and automatically releases the engaged tension line as a function of a tension release setting selected by the operator and, furthermore, makes shackling and unshackling of the coupling element of the line, respectively, to and from a hook easy and convenient.